Add StringUtils to /contracts on NPM, change hash to Poseidon for DKIM hashing, include zk regex bug

What's Changed

2.0.0 -> 3.1.3

• Use Poseidon for DKIM hash by @saleel in #115
• [Sora] Use zk regex by @Divide-By-0 in #117
• chore(deps): bump @babel/traverse from 7.21.2 to 7.23.2 in /packages/e2e-lambdatest by @dependabot in #123
• Add DKIMRegistry interface by @saleel in #122
• Fix shift malleability attack. by @SoraSuegami in #124

3.1.3 -> 3.2.0

• add string utils to have packsize improvements from zkp2p by @Divide-By-0 in #125

Note that the pre-generated regex contracts have not been updated to fix the shift malleability attack on zk regex. You MUST update your circuits to use ShiftAndPackMaskedStr instead of ShiftAndPack in order to be secure.

As usual, to get this release, use NPM:

yarn add @zk-email/circuits@latest
yarn add @zk-email/contracts@latest

Full Changelog: 2.0.1...v3.1.4